不同尖锐度纹理形状的摩擦触觉感知与表征研究

通过开展触觉感知不同尖锐度纹理形状的接触摩擦特性、主观认知行为和功能核磁共振试验，从皮肤的“感”、大脑的“知”和主观的“评”全面系统地对不同纹理形状的摩擦触觉感知进行了量化表征研究. 研究表明：接触摩擦力、主观评价、激活脑区面积和强度是表征摩擦触觉感知的有效参数. 触摸不同纹理表面的摩擦力中黏着摩擦力比形变摩擦力占比大，触摸平角纹理的摩擦力最大，尖角纹理的摩擦力最小. 黏着感主要受接触面积和黏着摩擦力的影响；尖锐感主要受触觉感受体所受应力和形变摩擦的影响；而舒适感受到表面摩擦机制和触觉感受体所受应力综合影响. 触觉感知纹理形状激发的大脑功能区以躯体感觉皮层为主，激活脑区主要位于中央前回和后回. 触摸过程的舒适感与激活脑区大小和强度成反比，舒适感差的纹理激发的脑区范围和强度大，且存在负激活现象.

By conducting experiments on contact friction characteristics, subjective cognitive behaviors and functional magnetic resonance imaging (fMRI) for tactile perception of textured shapes with different sharpness levels, this study systematically and comprehensively quantifies and characterizes friction-based tactile perception of various textured shapes from three perspectives: cutaneous sensation, cerebral cognition and subjective evaluation. The study demonstrates that contact friction force, subjective evaluation, and the area and intensity of activated brain regions are effective parameters for characterizing friction-based tactile perception. Among the friction forces when touching different textured surfaces, adhesive friction force accounts for a larger proportion than deformation friction force: the friction force is the largest for straight-angle textures and the smallest for sharp-angle textures. Adhesive sensation is mainly affected by contact area and adhesive friction force; sharpness sensation is primarily influenced by the stress on tactile receptors and deformation friction; while comfort sensation is comprehensively affected by surface friction mechanisms and the stress on tactile receptors. The brain functional regions activated by tactile perception of textured shapes are mainly the somatosensory cortex, with activated brain regions primarily located in the precentral gyrus and postcentral gyrus. The comfort sensation during the touching process is inversely proportional to the area and intensity of activated brain regions. Textures with poor comfort sensation trigger larger brain region areas and higher intensities, and negative activation phenomena are observed.